The present invention relates to a method for operating a fuel cell with a porous gas diffusion electrode to which an oxidizing or reducing gas is fed. In particular, the electrode is regenerated and/or the fuel cell is put out of service for a prolonged stretch of time.
British Patent Specification No. 1,215,630 describes a method in which the polarization of a gas diffusion electrode is reduced by absorbing liquid electrolyte into the pores of the electrode. To this end gas fed to the fuel cell is temporarily reduced to zero in an abrupt fashion to lower the pressure in the cell in such a way as to cause the electrolyte present in the cell to be drawn into the pores of the porous electrode. Such a process has the disadvantage that the carefully balanced three- phase equilibrium in the pores is disturbed. At the same time, the proper operation of the fuel cell is disturbed, so that after treatment it is not readily restored to the proper stationary working condition. The sudden changes in pressure also constitute a major drawback, particularly if the fuel cells are composed to a battery, as the control and proper functioning of the battery as a whole is seriously hampered in such a case.